The invention relates to a method for the air conditioning of a vehicle interior as a function of incident solar radiation.
German patent document DE 40 24 431 A1 discloses an air conditioning system with an incident solar radiation sensor arrangement having a plurality of sensor elements. In this case, first, the intensity and direction of the incident solar radiation are determined from the individual sensor output signals, after which these two variables serve for controlling an air conditioning system and further vehicle-side assemblies.
Also in a circuit arrangement, known from German patent document DE 43 05 446 A1, which includes an incident solar radiation sensor arrangement having a plurality of sensor elements. The intensity and direction of the incident solar radiation are first determined from individual sensor element output signals, after which these two variables serve for controlling an air conditioning system and further vehicle-side assemblies.
U.S. Pat. No. 4,760,772 likewise discloses an air conditioning system with an incident solar radiation sensor arrangement having three sensor elements, of which one is assigned to the vehicle front region and the other two are assigned to the two vehicle side regions or alternatively having four sensor elements, of which one is assigned to the vehicle front region, one is assigned to the vehicle rear region and the other two are assigned to the two vehicle side regions. In each case the intensity and direction of the incident solar radiation are determined from the sensor element output signals by means of a following computer unit, so that the air conditioning capacity of the air conditioning system can be set differently for various vehicle interior regions by means of these two calculated variables.
In U.S. Pat. No. 5,186,682, as in U.S. Pat. No. 4,760,772, the signal from two lateral incident solar radiation sensors of a common air conditioning unit is evaluated in terms of the intensity and direction of incidence of the sunlight. The single air conditioning controller unit then activates the existing air conditioning ducts as a function of the determined intensity and direction of the incident solar radiation.
Finally, German patent document DE 195 44 893 C2 discloses an air conditioning system for the air conditioning of a vehicle interior as a function of incident solar radiation, with at least two air conditioning ducts of individually controllable air conditioning capacity for the air conditioning of different vehicle interior regions, and with an incident solar radiation sensor arrangement having a plurality of sensor elements for detecting the incident solar radiation in different solid angle ranges. Each air conditioning duct is individually assigned its own sensor element of the incident solar radiation sensor arrangement and its own air conditioning controller unit. The sensor element assigned in each case detects the incident solar radiation essentially with a restriction to that solid angle range which corresponds positionally to the vehicle interior region air-conditioned by the respective air conditioning duct. The air conditioning controller unit assigned in each case sets the air conditioning capacity of the respective air conditioning duct as a function of the output signal from only the assigned sensor element of the incident solar radiation sensor arrangement.
Thus, by means of this prior art, an individual air conditioning of various regions of the vehicle interior as a function of incident solar radiation is possible.
However, the incident solar radiation sensor arrangement supplies only the solar values of the individual zones and the average value of these. The solar value of the individual zones is in this case used directly as a factor characteristic curve for temperature or blower regulation as a function of the outside temperature. That is the blown-air temperature is lowered as a result of the Sun's influence or the blower level is raised. This does not allow for whether the Sun is high or low with respect to the vehicle.
When the Sun is very high, all the values of the sensor elements of the incident solar radiation sensor arrangement have approximately the same value. Depending on the strength of the incident radiation, the values are higher or lower. In complete darkness, the sensor values indicate 0%, while, in the case of very strong incident solar radiation, the sensor values indicate a maximum of 125%. In the case of a very high solar load and when the Sun is very high, this means, for air conditioning regulation, that, although there is no incident solar radiation acting on the vehicle occupants since the incident solar radiation takes place on the vehicle roof and not through a window into the interior, in all the zones the blow-out temperature is lowered very sharply or the blower fraction is increased very sharply as a result of the incident solar radiation. This air conditioning regulation, however, is faulty and is very uncomfortable for the occupant/occupants.
The object of the present invention is, therefore, to develop the generic air conditioning system for the air conditioning of a vehicle interior as a function of incident solar radiation and a method for operating the air conditioning system in such a way that the abovementioned faulty air conditioning regulation which is very uncomfortable for the occupant/occupants is eliminated.
As a result of the calculation of the steepness of the sunlight or of the laterally specific incident solar radiation, it is possible, during automatic blower operation, to react to and counteract in a more focused manner the influencing factors/disturbing variables acting on the vehicle from outside, such as, for example, incident solar radiation from one side or steeply angled sunlight. The occupants, by manual action, can set the blower even more individually to their requirements. A marked improvement in air conditioning comfort is thereby achieved for the individual seat positions.
This and further objects, features and advantages of the present invention become obvious for the following description of a preferred exemplary embodiment of the invention, in conjunction with the drawing in which: